It is well known that a developer for silver halide photographic materials generally contains at least a developing agent for reducing silver halide, a development accelerator, a preservative for preventing the occurrence of fatigue of the developer by oxidation, and an antifoggant. More particularly, the preservative prevents the developing agent from being oxidized by oxygen dissolved in the aqueous solution from the air, thus losing developing power, and sodium sulfite is most usually used as a preservative. However, when a large amount of sodium sulfite preservative is used in a developing agent for silver halide color photographic materials, coloring hindrance undesirably occurs. Therefore, for a developer for silver halide color photographic materials, hydroxylamine has been widely used as a preservative.
On the other hand, recently, it has been clarified that when iron ions enter the developer containing hydroxylamine, fogging of images is increased. This phenomenon is considered to be caused by ammonia generated by the catalystic action of the iron ions for the decomposition reaction of the hydroxylamine, and it has been reported that the problem can be overcome by adding 1,3-diamino-2-propanol-N,N,N',N'-tetraacetic acid to the developer as a chelating agent (P. J. Twist's report in International Congress of Photographic Science, (1982)). However, the improvement is insufficient.
Also, in color photographic materials, it is common to use a so-called DIR compound (development inhibitor releasing compound) capable of forming in the silver halide emulsion layers of the color photographic materials a development inhibitor in an amount corresponding to the coloring amount during the color development to improve the sharpness of the color film and the color reproducibility by the color correction effect.
In this case, however, if an antifoggant which is the released group of the DIR compound is accumulated in the developer, it undesirably reduces the sensitivity of the color photographic materials. Recently, for preventing the occurrence of environmental pollution, it is preferred to reduce the amounts of processing chemicals used in order to reduce the total amount of the waste processing solutions. However, in the foregoing case, it takes a long period of time to replace the developer in a development tank with a supplement solution, whereby the development inhibitor, which is the released group of the DIR compound, is accumulated to reduce the sensitivity (see Japanese Patent Application (OPI) No. 151944/82 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application")).
It is known that such problems can be reduced by incorporating light-insensitive fine grain silver halide emulsions capable of trapping the foregoing development inhibitor precipitating in the developer, as described in Japanese Patent Application (OPI) No. 23228/75. However, the existence of such a light-insensitive fine grain silver halide increases the formation of fog when iron ions enter the developer containing hydroxylamine. It has also been confirmed that such an action is more striking in the case of existence of colloidal silver grains in a yellow filter having a physical activity causing physical development.